Jom-Bolok volcanic field
| Jom-Bolok | |
|---|---|
 | |
| Highest point | |
| Elevation | 2,077 m (6,814 ft)  |
| Coordinates | 52°42′0″N 98°58′48″E / 52.70000°N 98.98000°E |
| Geography | |
  Jom-Bolok Location of Jom-Bolok in Russia | |
| Geology | |
| Age of rock | Pleistocene-Holocene |
| Last eruption | 682–779 CE |
Jom-Bolok, also known as Volcano Valley
Volcanic activity in the field commenced during the late Pleistocene in an area that had been previously influenced by glaciers and with even earlier volcanic and tectonic activity. Magma probably formed during deglaciation was erupted during the early Holocene, generating the long lava flow. A much more recent eruption in the southern part of the field may be referenced in Mongolian chronicles.
Geologic context
The Jom-Bolok volcanic field lies in the over 3,100 metres (10,200 ft) high East
Like the Udokan plateau, Jom-Bolok is a volcanic field part of the Baikal rift which has been volcanically active during the Holocene. Volcanism there may be the consequence either of passive rifting or mantle plume activity and has been ongoing since the Mesozoic.[8] The basement of this area was heavily folded and altered during the Tertiary, which was also affected by river incision and earlier eruptive activity.[9] During the late Pleistocene, 300–400 metres (980–1,310 ft) thick glaciers formed in the Jom-Bolok valley and other adjacent valleys.[10]
Geology
The field contains
An
The Kropotkin and Peretolchin cones are the largest ones and grew to heights of 100 metres (330 ft) above lava flows, Atkinson cone later formed on Peretolchin's side but is heavily degraded.[11] The Atkinson cone was probably formed during at least two separate stages, as did the Stariy cone which was destroyed during the early phase of activity and subsequently grew a secondary cone.[16]
A shorter, 6 kilometres (3.7 mi) long lava flow forms the southern lava field,
All the lavas at Jom-Bolok are hawaiites and comparable to the close but older Oka and Tuva field lavas;[14] the total volume of volcanic rocks is about 16 cubic kilometres (3.8 cu mi).[1] Other fields around the Baikal rift have also hawaiites but are also associated with other volcanic rocks.[19]
-
A lava flow -
Peretolchin
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Climate, vegetation and basement rocks
The climate is dominated by the
Eruption history
Volcanic activity in the field started 13,000
The youngest lavas are even more recent in age, 682–779 CE. One hypothesis formulated in 2015 assumes that the Irkut-Oka plateau may be the Ergune-Kun locality referenced in Mongolian chronicles. According to Mongolian chronicles 400 years before the birth of Genghis Khan the Mongols left Ergune-Kun under the lead of a Borte Chino, in coincidence with an event involving fire. The hypothesis suggests that the leaving of the Mongols coincides with the most recent eruption of Jom-Bolok which was witnessed by the Mongols and included in their chronicles.[26]
The field probably formed in two stages, the long lava flow formed in the first stage in the Hee-Gol valley directly followed by the Atkinson, Ostanets, Peretolchin and Pogranichniy cones.[12] The southern lava flow was preceded by the Stariy cone forming activity, at the end of the southern flow activity the Kropotkin and Treshina cones formed.[17] Another theory believes the Stariy and Treshina cones formed first in the whole field.[10] The most recent model states that Staryi and Treshchina erupted in the first phase, their lavas being buried beneath more recent eruption products. Atkinson, Ostanets and Peretolchin shortly afterwards then filled the valley with lava. Kropotkin erupted in the third phase and Pogranichnyi in the fourth, both being accompanied by activity at additional vents and the latter taking place about 900 years ago.[27][28]
Volcanic activity such as at Jom-Bolok can cause the injection of SO
2 into the atmosphere. When such gas reaches the stratosphere it can cause temperature anomalies named volcanic winters. In the case of the northern field of Jom-Bolok, the total amount of SO
2 reaching the upper troposphere would be about 50–60 megatonnes (49,000,000–59,000,000 long tons; 55,000,000–66,000,000 short tons) if one assumes a similar eruption in style to the Laki eruptions, which however took place at latitudes with a lower stratosphere.[7] Local lakes show no evidence of tephra influence.[29]
References
- ^ a b Shchetnikov and Bezrukova 2019, p.1824
- ^
- ^ a b Shchetnikov, Bezrukova and Krivonogov 2019, p.291
- ^ Ivanov et al. 2011, p.1279
- ^ Arzhannikov et al. 2017, p.21
- S2CID 234857561.
- ^ a b c Ivanov et al. 2011, pp.1288–1289
- .
- .
- ^ a b c d Arzhannikov et al. 2016, p.89
- ^ a b c d Ivanov et al. 2011, p.1282
- ^ a b c Ivanov et al. 2011, p.1285
- ^ a b Ivanov et al. 2011, pp.1280–1281
- ^ a b c d Ivanov et al. 2011, p.1287
- ^ a b c Arzhannikov et al. 2016, p.90
- ^ a b Ivanov et al. 2011, p.1284
- ^ a b c Ivanov et al. 2011, p.1286
- ^ a b Shchetnikov, Bezrukova and Krivonogov 2019, p.293
- ^ a b Ivanov et al. 2011, pp.1290–1291
- ^ Bezrukova et al. 2021, p.937
- ^ Shchetnikov and Bezrukova 2019, p.1827
- ^ Bezrukova et al. 2021, p.936
- ^ Arzhannikov et al. 2017, p.20
- ^ Shchetnikov, Bezrukova and Krivonogov 2019, p.301
- ^ Shchetnikov, Bezrukova and Krivonogov 2019, p.292
- ^ Arzhannikov et al. 2016, pp.97–98
- ^ Arzhannikov et al. 2017, p.22
- ^ Arzhannikov et al. 2017, p.36
- ^ Bezrukova et al. 2021, p.942
Sources
- Arzhannikov, S.G.; Ivanov, A.V.; Arzhannikova, A.V.; Demonterova, E.I.; Jolivet, M.; Buyantuev, V.A.; Oskolkov, V.A.; Voronin, V.I. (August 2016). "The most recent (682–792 CE) volcanic eruption in the Jombolok lava field, East Sayan, Central Asia triggered exodus of Mongolian pre-Chinggis Khaan tribes (778–786 CE)" (PDF). Journal of Asian Earth Sciences. 125: 87–99. S2CID 130023892.
- Arzhannikov, S.G.; Ivanov, A.V.; Arzhannikova, A.V.; Demonterova, E.I.; Jolivet, M.; Voronin, V.I.; Buyantuev, V.A.; Oskolkov, V.A. (January 2017). "Age of the Jombolok lava field (East Sayan): evidence from dendrochronology and radiocarbon dating". Russian Geology and Geophysics. 58 (1): 20–36. ISSN 1068-7971.
- Bezrukova, Elena V.; Shchetnikov, Alexander A.; Kulagina, Natalia V.; Amosova, Alena A. (October 2021). "Lateglacial and Holocene vegetation and environmental change in the Jom-Bolok volcanic region, East Sayan Mountains, South Siberia, Russia". Boreas. 50 (4): 935–947. S2CID 233693197.
- Ivanov, Alexei V.; Arzhannikov, Sergei G.; Demonterova, Elena I.; Arzhannikova, Anastasia V.; Orlova, Lyubov A. (28 April 2011). "Jom-Bolok Holocene volcanic field in the East Sayan Mts., Siberia, Russia: structure, style of eruptions, magma compositions, and radiocarbon dating". Bulletin of Volcanology. 73 (9): 1279–1294. S2CID 129870314.
- Shchetnikov, Alexander A.; Bezrukova, Elena V.; Krivonogov, Sergey K. (April 2019). "Late Glacial to Holocene volcanism of Jom-Bolok Valley (East Sayan Mountains, Siberia) recorded by microtephra layers of the Lake Kaskadnoe-1 sediments". Journal of Asian Earth Sciences. 173: 291–303. S2CID 134449935.
- Shchetnikov, Alexander; Bezrukova, Elena V. (1 November 2019). "Lakes of the Jom-Bolok Volcanoes Valley in the East Sayan Mts., Baikal region". Journal of Geographical Sciences. 29 (11): 1823–1840. ISSN 1861-9568.